A whole spectrum of chitosanases are now known (for more details, see {http://rbrzezinski.recherche.usherbrooke.ca/::http://rbrzezinski.recherche.usherbrooke.ca/}). They can hydrolyse various types of links in chitosan. The only constant property is the endohydrolysis of GlcN-GlcN links, which is common to all known chitosanases. One known chitosanase is limited to this link recognition [4], while the majority can also recognize GlcN-GlcNAc links or GlcNAc-GlcN links but not both. They also do not recognize GlcNAc-GlcNAc links in partly acetylated chitosan.